<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script src="./js/vue.js"></script>
    <div class="box">
        <h1>{{msg}}</h1>
    </div>
    <script>
        // Vm_extend 相当于Vue的子类
        const Vm_extend=Vue.extend({
            data(){
                return {
                    msg:'xianggansha'
                }
            }
        })
        new Vm_extend().$mount('.box');
    </script>
</body>
</html>